This invention relates to a high precision boring tool, and more particularly to a novel tool bit or insert holding cartridge therefor. Even more particularly this invention relates to a novel method of producing an adjustable tool cartridge for use with high precision boring tools.
Heretofore it has been customary to provide boring tools with adjustable tool holders, which can be adjusted radially of the axis of rotation of the associated boring head, thereby to increase or decrease the diameter inscribed by the tool. In U.S. Pat. No. 4,398,854, for example, the tool holder is mounted for radial adjustment in the head of a boring bar by means of a rotatable adjusting screw, which has a shank that threads into a bronze nut secured in the inner end of the tool holder. By rotating the adjusting screw the tool holder can be advanced inwardly or outwardly of a bore formed in the boring bar head transversely of its axis.
While tool adjusting means of the type disclosed in the above-noted patent enables ready radial adjustment of the tool bit it does not eliminate undesirable backlash which can result because of any lost motion or play as between the adjusting screw and nut connection which functions to adjust the tool. Moreover, the adjusting means disclosed in this prior art patent comprises several cooperating elements which must be carefully machined to enable even a modest degree of accuracy to be achieved by the adjusting means. It is an object of this invention, therefore, to provide for a boring tool a novel tool cartridge having therein improved tool adjusting means, which substantially eliminates any. undesirable backlash that might occur during the adjustment of the tool, thereby providing a substantially improved precision boring tool.
Another object of this invention is to provide a novel cartridge of the type described, which can be made and utilized separately from any given boring bar, and hence can be produced and marketed for use with any one of a variety of different types of boring bars.
Still another object of this invention is to provide a novel method of producing an adjustable boring bar cartridge of the type described, and which method minimizes the need for the accurate machining of various parts which are utilized in producing the adjusting mechanism for the cartridge.
Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims,particularly when read in conjunction with the accompanying drawings.